Overflow plumbing help

[yoelf]

Hey,
I started this hobby a couple months ago and I slowly buy parts for my build so I often end up upgrading the "older" part.
I have a 40gl breeder bashsea ss-30 sump a PF-300 overflow and a COR-20 pump (bottle neck I know) I thought if I run the Cor on a lower setting to match the overflow I would be fine well not exactly lol
I finally saved up enough for the Cor-20 their sale helped but my tank overflows pretty quick even on the lowest setting which I thought would be below 300gph and my Eshopps pf-300 would be able to handle it but it doesn't from the quality to the "specs" of the OF I'm kinda disappointed what is a better overflow I can easily install is there something I can configure to make my current one work?
Any advice on how I should proceed would be welcomed
Thank You

 

[yoelf]

Here’s my current setup

 

[reeferkeeperabq]

Here’s my current setup

I need a little bit to wrap my head around, however seems to me, you may have been in a bit of a rush. Your sump looks rather large in water volume for a 40 gal tank. I can imagine it would fill it up rather quickly especially with a pump high in gph. I would possibly look at a new "smaller pump, im thinking smaller diameter hose for return. I can think of a variety of things you can buy, or do to solve your problems, but I think you juat need to rethink your current equipment. I could be very wrong. I want someone else to chime In, it's 1:35am right now, so I won't get to checking out all your specs for everything tonight. Hope all is well and your not pulling your hair out. I just started to cycle my 2nd tank. Its a (90 gal with eshopps rs 100)

 

[homer1475]

Gate valve on the return line so you can throttle down the pump to match the overflow. Won't hurt the pump one bit as it's just like adding head pressure.

Simple and effective fix.

 

[yoelf]

Gate valve on the return line so you can throttle down the pump to match the overflow. Won't hurt the pump one bit as it's just like adding head pressure.

Simple and effective fix.

*Hands over virtual master aquatic plumber trophy*
yes I got the same answer from 2 other people it worked!!!
Just need to fine tune it.
Got a Y fitting so I can do easy water changes or add whatever I want to it.
Thank you